package org.apache.commons.graph.builder

import org.apache.commons.graph.MutableGraph

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * TODO Fillme!!
 *
 * @param <V> the Graph vertices type
 * @param <E> the Graph edges type
</E></V> */
interface GraphConnector<V, E> {
    /**
     * Adds a new edge to graph.
     *
     * @param <A> the Graph edges type
     * @param arc the edge to add.
     * @return the [HeadVertexConnector]
    </A> */
    fun <A : E> addEdge(arc: A): HeadVertexConnector<V, E>

    /**
     * Adds a new vertex to graph.
     *
     * @param <N> the Graph vertices type
     * @param node the vertex to add
     * @return the vertex added
    </N> */
    fun <N : V> addVertex(node: N): N

    infix  fun<N : V,N2 : V,A : E> Pair<N,N2>.edge(arc:A) = addEdge(arc).from(first).to(second)

    infix  fun<N : V,N2 : V,A : E> A.edgeOn(ab:Pair<N,N2>) = addEdge(this).from(ab.first).to(ab.second)

    infix  fun<N : V,A : E> A.from(a:N) = addEdge(this).from(a)

    infix  fun<N : V,A : E> N.on(arc:A) = addEdge(arc).from(this)

}

internal class DefaultGrapher<V, E>(
    private val graph: MutableGraph<V, E>
) : GraphConnector<V, E> {

    override fun <A : E> addEdge(arc: A): HeadVertexConnector<V, E> {
        //var arc = arc
        //arc = Assertions.checkNotNull(arc, "Null edge not admitted")
        return DefaultHeadVertexConnector(graph, arc)
    }

    override fun <N : V> addVertex(node: N): N {
        //var node = node
        //node = Assertions.checkNotNull(node, "Null vertex not admitted")
        graph.addVertex(node)
        return node
    }

}